1. Field of the Invention
The present invention relates to an endoscope system including an endoscope having an insertion section which is insertable into a cavity under inspection and an operation section to which a proximal end of the insertion section is connected, and a disposable protection cover having an insertion section cover for covering the insertion section of the endoscope and an operation section cover for covering the operation section of the endoscope.
2. Related Art Statements
An endoscope system has been widely utilized for providing diagnostic and therapeutic indications for coeliac cavities of patients and for internal inspection of mechanical structures. To this end, various kinds of endoscope have been developed. For instance, in order to inspect or treat the oesophagus, stomach and duodenum, upper endoscopes have been utilized. Further, colonoscopes have been developed to examine colons and sigmoidoscopes have been proposed to inspect rectums and sigmoid colons. When the endoscope is used, an insertion portion of the endoscope has to be inserted into a cavity of a patient, so that the outer surface of the insertion section of the endoscope is contaminated with living tissues and liquids. Such a contaminated endoscope could not be successively used for other patients. Therefore, once the endoscope is used to diagnose and/or treat a patient, it is necessary to clean and sterilize the endoscope. Of course, the cleaning of the endoscope requires a substantial amount of time and during this cleaning time, it is impossible to perform the endoscopic procedure by using this endoscope. In order to mitigate such an idle time, it is necessary to prepare a large number of endoscopes. However, endoscopes are rather expensive, so that it is practically difficult to prepare a large number of endoscopes, particularly in a small hospital or clinic. Therefore, in almost all hospitals and clinics, in practice, after the endoscope has been used for examining or treating a patient, the endoscope is immediately cleaned. Typically, this cleaning requires several minutes to ten minutes. In order to effect complete washing and sterilization, the cleaning has be to performed for several tens of minutes.
Further, the endoscope has various channels such as a air channel, a water channel, a suction channel, and a forcep channel which extend along the insertion section from a proximal end to a distal end thereof, and these channels, except for the forceps channel, are connected via tubes to respective devices such as an air supply pump, a water supply pump, a water suction pump and an air suction pump. These channels are subjected to contact with living tissues and liquids. However, in order to clean these channels of the endoscope completely, a relatively long period of time is required. Thus, the endoscope can not be utilized efficiently during the long cleaning time. In a large hospital or clinics, a large number of endoscopes may be prepared in order to mitigate the problem of cleaning time. However, this solution results in an increase in operating cost. Further, in small clinics, it is practically impossible to prepare a number of expensive endoscopes.
Moreover, the endoscope might be broken during cleaning and the usable life of the endoscope is liable to be shortened by the cleaning.
In order to avoid the above explained various problems, there has been proposed an endoscope system, in which the endoscope is covered with a disposable protection sheath-like cover having channels formed therein. For instance, U.S. Pat. Nos. 4,721,097, 4,741,326, 4,825,850, 4,869,238, 4,991,564, 4,991,565, 5,050,585 disclose various kinds of the disposable protection sheath-like covers having channels formed therein. In U.S. Pat. No. 4,646,722, there is shown an endoscope system in which the endoscope is covered with a protection sheath, while a tube having channels formed therein is inserted into a U-shaped cutout formed in an outer surface of the endoscope along a longitudinal axis thereof. Upon diagnosis, the insertion section of the endoscope is covered with the protection sheath, and after the inspection, the sheath is removed from the insertion section and is then discarded. Therefore, it is no longer necessary to clean the endoscope after every inspection.
In the above mentioned U.S. Patent Specifications, the protection sheath-like cover is constructed to cover only the insertion section of the endoscope, but does not cover an operation section of the endoscope. It should be noted that the operation section of the endoscope is handled by doctors and operators and thus is brought into contact with the living tissues and liquids of a patient. Therefore, in order to remove the contamination of the operation section of the endoscope due to such living tissues and liquids, it is advantageous to cover not only the insertion section, but also the operation section of the endoscope. In European Patent Publication No. 0 349 479 A1, there is disclosed an endoscope system, in which not only the insertion section, but also the operation section of the endoscope are covered with a disposable protection cover. That is to say, the protection cover comprises a sheath-like portion for covering the insertion section of the endoscope and a bag-like portion for covering the operation section, the sheath-like portion and bag-like portion being integrally formed. It has been also proposed to form the sheath-like portion and bag-like portion as separate covers. For instance, in European Patent Publication No. 0 341 719 A1, there is proposed another known endoscope system, in which an insertion section of an endoscope is covered with a sheath-like disposable protection cover and an operation section of the endoscope is covered with a bag-like cover disposable protection which is mated or joined with the sheath-like cover in order to prevent the contamination through the junction of the sheath-like cover and the bag-like cover.
In the known endoscope system including the insertion section cover having an insertion section inserting channel and a forceps channel, the construction of the forceps channel, e.g. length, inner diameter, strength, material, configuration and shape is not formed such that various forceps, i.e. treating tools for ordinary without-cover (coverless) endoscopes, which are not used together with the disposable protection covers, can be commonly used for the endoscope system. That is to say, specially prepared forceps are provided for use in the endoscope system. As is apparent, this is very inconvenient and is not economical. Further, if a forceps for a coverless endoscope is erroneously used for the endoscope system including the endoscope and disposable protection cover, either or both of the forceps and the protection cover might be broken.
Further, in the known endoscope system, various kinds of forceps are prepared and a desired forceps is used. In the present specification, two forceps for performing the same treatment but having different outer diameters are considered to belong to different kinds of forceps. It should be noted that the outer diameter means a maximum diameter of a forceps and generally a diameter of a distal end treating portion. As stated above, there have been proposed various kinds of forceps for use in the ordinary coverless endoscopes and these forceps can be classified into several groups in accordance with the outer diameter. Similarly, various kinds of forceps for use with disposable protection covers of the above mentioned endoscope system can be classified into several groups in accordance with the outer diameters. However, the forceps groups for the disposable protection covers are not mated with the forceps groups for the coverless endoscopes. This means that the forceps for the coverless endoscopes can not be commonly used for the disposable protection covers, and thus sometimes suitable treatments can not performed. Moreover, an operator can not utilize the familiar forceps for the coverless endoscopes, so that the operator might be subjected to mental stress.
For coverless endoscopes, there have been prepared a very large number of different kinds of forceps, and thus the number of groups of forceps is quite large. However, in the endoscope system including the disposable protection cover a the forceps channel and the endoscope without a forceps channel, it is desired to discard the forceps together with the cover. Therefore, it is desired to prepare forceps which are classified into a smaller number of groups.
In the above mentioned endoscope system including the endoscope and disposable protection cover with forceps channel, a position of the forceps channel in a cross section, at the distal end of the insertion section cover, is not identical with a position of the forceps channel in a cross section at a connecting portion between the insertion section cover and the operation section cover. In other words, the forceps channel is twisted within the insertion section cover. Thus, the forceps can not be smoothly inserted into the forceps channel and a relatively large force is required for inserting the forceps. Furthermore, during the insertion of the forceps, a tip of the forceps might be hit on an inner wall is the forceps channel and might be broken or the inner wall damaged. The above mentioned drawback is manifest when a length of the forceps is long. When the forceps channel is twisted, the forceps channel is clogged upon bending the protection cover, and therefore the forceps could not be inserted any more.
In the known disposable protection cover, the operation section cover for covering the operation section of the endoscope is made of soft material, because the operating members provided on the operation section have to be operated on the protection cover. That is to say, if the operation section cover is made of rigid or semi-rigid material, the operating members could not be operated positively. Therefore, the operation section cover might move relative to the operation section of the endoscope. This results in that the operator can not grasp the operation section firmly, and therefore the operator can not handle the operation section effectively and might be subject to fatigue.